linux/net/batman-adv/send.c
Marek Lindner 32ae9b221e batman-adv: Make bat_priv->primary_if an rcu protected pointer
The rcu protected macros rcu_dereference() and rcu_assign_pointer()
for the bat_priv->primary_if need to be used, as well as spin/rcu locking.

Otherwise we might end up using a primary_if pointer pointing to already
freed memory.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-05-01 22:49:03 +02:00

599 lines
17 KiB
C

/*
* Copyright (C) 2007-2011 B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*
*/
#include "main.h"
#include "send.h"
#include "routing.h"
#include "translation-table.h"
#include "soft-interface.h"
#include "hard-interface.h"
#include "vis.h"
#include "aggregation.h"
#include "gateway_common.h"
#include "originator.h"
static void send_outstanding_bcast_packet(struct work_struct *work);
/* apply hop penalty for a normal link */
static uint8_t hop_penalty(const uint8_t tq, struct bat_priv *bat_priv)
{
int hop_penalty = atomic_read(&bat_priv->hop_penalty);
return (tq * (TQ_MAX_VALUE - hop_penalty)) / (TQ_MAX_VALUE);
}
/* when do we schedule our own packet to be sent */
static unsigned long own_send_time(struct bat_priv *bat_priv)
{
return jiffies + msecs_to_jiffies(
atomic_read(&bat_priv->orig_interval) -
JITTER + (random32() % 2*JITTER));
}
/* when do we schedule a forwarded packet to be sent */
static unsigned long forward_send_time(void)
{
return jiffies + msecs_to_jiffies(random32() % (JITTER/2));
}
/* send out an already prepared packet to the given address via the
* specified batman interface */
int send_skb_packet(struct sk_buff *skb,
struct hard_iface *hard_iface,
uint8_t *dst_addr)
{
struct ethhdr *ethhdr;
if (hard_iface->if_status != IF_ACTIVE)
goto send_skb_err;
if (unlikely(!hard_iface->net_dev))
goto send_skb_err;
if (!(hard_iface->net_dev->flags & IFF_UP)) {
pr_warning("Interface %s is not up - can't send packet via "
"that interface!\n", hard_iface->net_dev->name);
goto send_skb_err;
}
/* push to the ethernet header. */
if (my_skb_head_push(skb, sizeof(struct ethhdr)) < 0)
goto send_skb_err;
skb_reset_mac_header(skb);
ethhdr = (struct ethhdr *) skb_mac_header(skb);
memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
skb_set_network_header(skb, ETH_HLEN);
skb->priority = TC_PRIO_CONTROL;
skb->protocol = __constant_htons(ETH_P_BATMAN);
skb->dev = hard_iface->net_dev;
/* dev_queue_xmit() returns a negative result on error. However on
* congestion and traffic shaping, it drops and returns NET_XMIT_DROP
* (which is > 0). This will not be treated as an error. */
return dev_queue_xmit(skb);
send_skb_err:
kfree_skb(skb);
return NET_XMIT_DROP;
}
/* Send a packet to a given interface */
static void send_packet_to_if(struct forw_packet *forw_packet,
struct hard_iface *hard_iface)
{
struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
char *fwd_str;
uint8_t packet_num;
int16_t buff_pos;
struct batman_packet *batman_packet;
struct sk_buff *skb;
if (hard_iface->if_status != IF_ACTIVE)
return;
packet_num = 0;
buff_pos = 0;
batman_packet = (struct batman_packet *)forw_packet->skb->data;
/* adjust all flags and log packets */
while (aggregated_packet(buff_pos,
forw_packet->packet_len,
batman_packet->num_hna)) {
/* we might have aggregated direct link packets with an
* ordinary base packet */
if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
(forw_packet->if_incoming == hard_iface))
batman_packet->flags |= DIRECTLINK;
else
batman_packet->flags &= ~DIRECTLINK;
fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
"Sending own" :
"Forwarding"));
bat_dbg(DBG_BATMAN, bat_priv,
"%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d,"
" IDF %s) on interface %s [%pM]\n",
fwd_str, (packet_num > 0 ? "aggregated " : ""),
batman_packet->orig, ntohl(batman_packet->seqno),
batman_packet->tq, batman_packet->ttl,
(batman_packet->flags & DIRECTLINK ?
"on" : "off"),
hard_iface->net_dev->name,
hard_iface->net_dev->dev_addr);
buff_pos += sizeof(struct batman_packet) +
(batman_packet->num_hna * ETH_ALEN);
packet_num++;
batman_packet = (struct batman_packet *)
(forw_packet->skb->data + buff_pos);
}
/* create clone because function is called more than once */
skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
if (skb)
send_skb_packet(skb, hard_iface, broadcast_addr);
}
/* send a batman packet */
static void send_packet(struct forw_packet *forw_packet)
{
struct hard_iface *hard_iface;
struct net_device *soft_iface;
struct bat_priv *bat_priv;
struct batman_packet *batman_packet =
(struct batman_packet *)(forw_packet->skb->data);
unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
if (!forw_packet->if_incoming) {
pr_err("Error - can't forward packet: incoming iface not "
"specified\n");
return;
}
soft_iface = forw_packet->if_incoming->soft_iface;
bat_priv = netdev_priv(soft_iface);
if (forw_packet->if_incoming->if_status != IF_ACTIVE)
return;
/* multihomed peer assumed */
/* non-primary OGMs are only broadcasted on their interface */
if ((directlink && (batman_packet->ttl == 1)) ||
(forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
/* FIXME: what about aggregated packets ? */
bat_dbg(DBG_BATMAN, bat_priv,
"%s packet (originator %pM, seqno %d, TTL %d) "
"on interface %s [%pM]\n",
(forw_packet->own ? "Sending own" : "Forwarding"),
batman_packet->orig, ntohl(batman_packet->seqno),
batman_packet->ttl,
forw_packet->if_incoming->net_dev->name,
forw_packet->if_incoming->net_dev->dev_addr);
/* skb is only used once and than forw_packet is free'd */
send_skb_packet(forw_packet->skb, forw_packet->if_incoming,
broadcast_addr);
forw_packet->skb = NULL;
return;
}
/* broadcast on every interface */
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
if (hard_iface->soft_iface != soft_iface)
continue;
send_packet_to_if(forw_packet, hard_iface);
}
rcu_read_unlock();
}
static void rebuild_batman_packet(struct bat_priv *bat_priv,
struct hard_iface *hard_iface)
{
int new_len;
unsigned char *new_buff;
struct batman_packet *batman_packet;
new_len = sizeof(struct batman_packet) +
(bat_priv->num_local_hna * ETH_ALEN);
new_buff = kmalloc(new_len, GFP_ATOMIC);
/* keep old buffer if kmalloc should fail */
if (new_buff) {
memcpy(new_buff, hard_iface->packet_buff,
sizeof(struct batman_packet));
batman_packet = (struct batman_packet *)new_buff;
batman_packet->num_hna = hna_local_fill_buffer(bat_priv,
new_buff + sizeof(struct batman_packet),
new_len - sizeof(struct batman_packet));
kfree(hard_iface->packet_buff);
hard_iface->packet_buff = new_buff;
hard_iface->packet_len = new_len;
}
}
void schedule_own_packet(struct hard_iface *hard_iface)
{
struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
struct hard_iface *primary_if;
unsigned long send_time;
struct batman_packet *batman_packet;
int vis_server;
if ((hard_iface->if_status == IF_NOT_IN_USE) ||
(hard_iface->if_status == IF_TO_BE_REMOVED))
return;
vis_server = atomic_read(&bat_priv->vis_mode);
primary_if = primary_if_get_selected(bat_priv);
/**
* the interface gets activated here to avoid race conditions between
* the moment of activating the interface in
* hardif_activate_interface() where the originator mac is set and
* outdated packets (especially uninitialized mac addresses) in the
* packet queue
*/
if (hard_iface->if_status == IF_TO_BE_ACTIVATED)
hard_iface->if_status = IF_ACTIVE;
/* if local hna has changed and interface is a primary interface */
if ((atomic_read(&bat_priv->hna_local_changed)) &&
(hard_iface == primary_if))
rebuild_batman_packet(bat_priv, hard_iface);
/**
* NOTE: packet_buff might just have been re-allocated in
* rebuild_batman_packet()
*/
batman_packet = (struct batman_packet *)hard_iface->packet_buff;
/* change sequence number to network order */
batman_packet->seqno =
htonl((uint32_t)atomic_read(&hard_iface->seqno));
if (vis_server == VIS_TYPE_SERVER_SYNC)
batman_packet->flags |= VIS_SERVER;
else
batman_packet->flags &= ~VIS_SERVER;
if ((hard_iface == primary_if) &&
(atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER))
batman_packet->gw_flags =
(uint8_t)atomic_read(&bat_priv->gw_bandwidth);
else
batman_packet->gw_flags = 0;
atomic_inc(&hard_iface->seqno);
slide_own_bcast_window(hard_iface);
send_time = own_send_time(bat_priv);
add_bat_packet_to_list(bat_priv,
hard_iface->packet_buff,
hard_iface->packet_len,
hard_iface, 1, send_time);
if (primary_if)
hardif_free_ref(primary_if);
}
void schedule_forward_packet(struct orig_node *orig_node,
struct ethhdr *ethhdr,
struct batman_packet *batman_packet,
uint8_t directlink, int hna_buff_len,
struct hard_iface *if_incoming)
{
struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
struct neigh_node *router;
unsigned char in_tq, in_ttl, tq_avg = 0;
unsigned long send_time;
if (batman_packet->ttl <= 1) {
bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
return;
}
router = orig_node_get_router(orig_node);
in_tq = batman_packet->tq;
in_ttl = batman_packet->ttl;
batman_packet->ttl--;
memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
/* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
* of our best tq value */
if (router && router->tq_avg != 0) {
/* rebroadcast ogm of best ranking neighbor as is */
if (!compare_eth(router->addr, ethhdr->h_source)) {
batman_packet->tq = router->tq_avg;
if (router->last_ttl)
batman_packet->ttl = router->last_ttl - 1;
}
tq_avg = router->tq_avg;
}
if (router)
neigh_node_free_ref(router);
/* apply hop penalty */
batman_packet->tq = hop_penalty(batman_packet->tq, bat_priv);
bat_dbg(DBG_BATMAN, bat_priv,
"Forwarding packet: tq_orig: %i, tq_avg: %i, "
"tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
batman_packet->ttl);
batman_packet->seqno = htonl(batman_packet->seqno);
/* switch of primaries first hop flag when forwarding */
batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
if (directlink)
batman_packet->flags |= DIRECTLINK;
else
batman_packet->flags &= ~DIRECTLINK;
send_time = forward_send_time();
add_bat_packet_to_list(bat_priv,
(unsigned char *)batman_packet,
sizeof(struct batman_packet) + hna_buff_len,
if_incoming, 0, send_time);
}
static void forw_packet_free(struct forw_packet *forw_packet)
{
if (forw_packet->skb)
kfree_skb(forw_packet->skb);
kfree(forw_packet);
}
static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
struct forw_packet *forw_packet,
unsigned long send_time)
{
INIT_HLIST_NODE(&forw_packet->list);
/* add new packet to packet list */
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/* start timer for this packet */
INIT_DELAYED_WORK(&forw_packet->delayed_work,
send_outstanding_bcast_packet);
queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
send_time);
}
/* add a broadcast packet to the queue and setup timers. broadcast packets
* are sent multiple times to increase probability for beeing received.
*
* This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
* errors.
*
* The skb is not consumed, so the caller should make sure that the
* skb is freed. */
int add_bcast_packet_to_list(struct bat_priv *bat_priv, struct sk_buff *skb)
{
struct hard_iface *primary_if = NULL;
struct forw_packet *forw_packet;
struct bcast_packet *bcast_packet;
if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
goto out;
}
primary_if = primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
if (!forw_packet)
goto out_and_inc;
skb = skb_copy(skb, GFP_ATOMIC);
if (!skb)
goto packet_free;
/* as we have a copy now, it is safe to decrease the TTL */
bcast_packet = (struct bcast_packet *)skb->data;
bcast_packet->ttl--;
skb_reset_mac_header(skb);
forw_packet->skb = skb;
forw_packet->if_incoming = primary_if;
/* how often did we send the bcast packet ? */
forw_packet->num_packets = 0;
_add_bcast_packet_to_list(bat_priv, forw_packet, 1);
return NETDEV_TX_OK;
packet_free:
kfree(forw_packet);
out_and_inc:
atomic_inc(&bat_priv->bcast_queue_left);
out:
if (primary_if)
hardif_free_ref(primary_if);
return NETDEV_TX_BUSY;
}
static void send_outstanding_bcast_packet(struct work_struct *work)
{
struct hard_iface *hard_iface;
struct delayed_work *delayed_work =
container_of(work, struct delayed_work, work);
struct forw_packet *forw_packet =
container_of(delayed_work, struct forw_packet, delayed_work);
struct sk_buff *skb1;
struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
struct bat_priv *bat_priv = netdev_priv(soft_iface);
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
hlist_del(&forw_packet->list);
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
goto out;
/* rebroadcast packet */
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
if (hard_iface->soft_iface != soft_iface)
continue;
/* send a copy of the saved skb */
skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
if (skb1)
send_skb_packet(skb1, hard_iface, broadcast_addr);
}
rcu_read_unlock();
forw_packet->num_packets++;
/* if we still have some more bcasts to send */
if (forw_packet->num_packets < 3) {
_add_bcast_packet_to_list(bat_priv, forw_packet,
((5 * HZ) / 1000));
return;
}
out:
forw_packet_free(forw_packet);
atomic_inc(&bat_priv->bcast_queue_left);
}
void send_outstanding_bat_packet(struct work_struct *work)
{
struct delayed_work *delayed_work =
container_of(work, struct delayed_work, work);
struct forw_packet *forw_packet =
container_of(delayed_work, struct forw_packet, delayed_work);
struct bat_priv *bat_priv;
bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
spin_lock_bh(&bat_priv->forw_bat_list_lock);
hlist_del(&forw_packet->list);
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
goto out;
send_packet(forw_packet);
/**
* we have to have at least one packet in the queue
* to determine the queues wake up time unless we are
* shutting down
*/
if (forw_packet->own)
schedule_own_packet(forw_packet->if_incoming);
out:
/* don't count own packet */
if (!forw_packet->own)
atomic_inc(&bat_priv->batman_queue_left);
forw_packet_free(forw_packet);
}
void purge_outstanding_packets(struct bat_priv *bat_priv,
struct hard_iface *hard_iface)
{
struct forw_packet *forw_packet;
struct hlist_node *tmp_node, *safe_tmp_node;
if (hard_iface)
bat_dbg(DBG_BATMAN, bat_priv,
"purge_outstanding_packets(): %s\n",
hard_iface->net_dev->name);
else
bat_dbg(DBG_BATMAN, bat_priv,
"purge_outstanding_packets()\n");
/* free bcast list */
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
&bat_priv->forw_bcast_list, list) {
/**
* if purge_outstanding_packets() was called with an argmument
* we delete only packets belonging to the given interface
*/
if ((hard_iface) &&
(forw_packet->if_incoming != hard_iface))
continue;
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/**
* send_outstanding_bcast_packet() will lock the list to
* delete the item from the list
*/
cancel_delayed_work_sync(&forw_packet->delayed_work);
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
}
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/* free batman packet list */
spin_lock_bh(&bat_priv->forw_bat_list_lock);
hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
&bat_priv->forw_bat_list, list) {
/**
* if purge_outstanding_packets() was called with an argmument
* we delete only packets belonging to the given interface
*/
if ((hard_iface) &&
(forw_packet->if_incoming != hard_iface))
continue;
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
/**
* send_outstanding_bat_packet() will lock the list to
* delete the item from the list
*/
cancel_delayed_work_sync(&forw_packet->delayed_work);
spin_lock_bh(&bat_priv->forw_bat_list_lock);
}
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
}